There are from BOS to Boston.
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There are 2 ways to travel from BOS to Boston. 2 ferries and 1 train are possible between the two areas. The train from BOS to BBY is the cheapest and fastest.
It's important to check each mode when booking your ticket so that you can find the best method for you. The cost of each type varies differently, so be sure to use Faretrotter to keep an eye out!